Apparatus and process for tapering artificial filaments



APPARATUS AND PROCESS FOR TAPERING ARTIFICIAL FILAMENT'S 2 Sheets-Sheet l J. J. GREGORY Filed Sept. 22, 1.942

May 1, 1945 INVENTOR. J J. (17256012 1 ATTORNEY y 1945- J. J. GREGORY 2,374,744

APPARATUS AND PROCESS FOR TAPERING ARTIFICIAL FILAMENTS ATTORNEY ?atented May 1, 1945 UNITED STATES PATENT OFFICE APPARATUS AND PROCESS FOR TAPERING ARTIFICIAL FILAMENTS John J. Gregory, Catonsville, Md., assignor to Pittsburgh Plate Glass Company,

Allegheny County, Pa., a corporation of Pennsylvania Application September 22, 1942, Serial No. 459,251

7 Claims.

. speed.

Another object of the invention is to provide an improved apparatus for manufacturing filaments having tapered sections.

In the manufacture of artificial filaments composed of organic plastics, it is desirable under certain conditions to vary the filament size at regular or irregular intervals in order to produce goods having desired characteristics. Filaments of varying denier, or composed of sections successively tapered, can be formed into yarns either alone or twisted in multiple relation with threads or other artificial filaments or natural'filaments r fibers. The filament structure can also be out along its length at the termination of each tapered portion which is of any lengthdesired. The cut sections can be employed in the manufacture of bristles for brushes or like structures.

Filamentsof the type referred to can be formed of organic plastics, such as cellulose acetate, cellulose nitrate or other cellulosic derivatives, for example, cellulose formate, propionate, or butyrate,

thiocarbamic or alkoxy-alkacyl esters of cellulose, 35

methyl, ethyl or benzyl'cellulose, or the condensation products of cellulose and glycols or other polyhydric alcohols. or artificial or natural resin, such as vinyl acetal, nylon, etc. The processes and structures herein described are applicable likewise to filaments or threads of varying or irregular denier produced by the wet or coagulation method Whether having a base of cellulose acetate or other organic derivatives of cellulose. or composed of regenerated cellulose, obtained by appropriate regeneration cuprammonium, or nitrocellulose silk.

In the drawings:

of viscose.

, in the apparatus; Fig. is a fragmentary elevation of another form of cam arrangement-Fig. 6 is a diagrammatic elevation of one type of filament produced by the apparatus; Fig. 7 is 9. diagrammatic plan of another type of filament produced by the apparatus; Fig. 8 is a fragmentary elevation of a synthetic bristle of another form;

Fig. 9 is a fragmentary elevation of a filament the latter.

such as that Fig. l is substantially a plan of an apparatus illustrating the principles of the invention and with portions shown in cross section; Fig. 2 is anend elevation of principal parts of the apparatus; Fig. 3 is a side elevation of portions of the structure shown in Fig. 2; Fig. 4 is a fraghaving a fiber core; and Fig. 10 is a diagrammatic elevation of extruding and collecting mechanism.

In practicing the invention, there is provided a'motor l0 connected by means of conventional gearing, such as pulleys l l and belt l2, in driving relation with a horizontal shaft ii that is mounted in bearings H5 in a frame 20. An end portion of theshaft has a cone pulley 2| rigidly mounted thereon and a belt 23 trained about this pulley is also trained about a companion cone pulley 24. which is rigidly mounted upon a second shaft 25. Suitable bearings 26 carry the shaft 25 horizontally upon the frame 20.

A belt shifter 28 of conventional form is mounted upon the frame 20 and includes a bar 29 slidably-mounted in guides 30 that are secured upon the frame. The belt 23 travels between rollers 3| that are mounted in spaced relation upon an end portion of the bar 29 and a handle 34 pivoted, as indicated at 36 upon the frame has a pivotal connection 38 secured to the bar 29 for operating An adjusting lever 39 mounted upon the handle 34 engages in notches 40 of a segmental plate 4| on the frame tohold the belt shifter in adjusted position. By manipulating the handle, the belt 23 can be shifted tochange the speed of the shaft 25 faster or slower than the speed of the shaft I5. It change in speed can be effected during the operation of the apparatus. However, satisfactory results have been attained by pro-adjusting the speed as desired for particular purposes. It is to be understood that the variable speed arrangement shown in connection with the cone pulleys is merely illustrative and that various other types of gears, sprockets, chains, etc. employed in variable speed mechanism can be adapted for the same purposes as those for which the apparatus referred to was designed.

The outer end of the shaft 25 has a gear 42 rig-idly mounted thereon for engagement with a similar gear 3 that is rigidly mounted upon the outer end of an axial shaft 45 of a screw pump casing communicates by mean of an inlet conmentary elevation-ofa cam arrangement included duit 54 with a supp y ta containing a pinis possible that the or propeller 52 is fitted, Thev by-pass conduit 65 connected rigidly to a upon the lower portion purpose of tilting the can thus be varied.

ning solution 58 of organic plastic which is pref- An outlet conduit 60 leading from the pump 50 is provided with a filter BI and at its outer end with a spinnerette 62 having openings 63 through which filaments 64 can be extruded in response to the operation of the pump. The filamentstructure can be composed of one or more strands. A connected to the outlet 60 is also connected to the inlet 54 for icy-passing a portion of the solution back into the pump casing.

to manipulate the truded.

An intermediate portion of the by-pass conduit 65 is provided with a gate valve 68 having an,

upright stem 69 pivotally connected, 'as-indicated at 10, to a lever 'II. The pivotal connection I includes a slotted portion 12 to provide for play in the relative movement of the parts involved. An intermediate portion of the lever II is pivoted, as indicated at 14, upon a bracket I that is rigidly mounted upon the frame 20. One end of the lever II opposite the connection to the valve stem 69 is provided with a roller 16 which is constantly pressed in contact with a cam 18 carried rigidly upon the shaft I5. The other end of the lever adjacent the valve stem is connected, as indicated at 19, to one end of a tension spring 90 and the other end of this spring has a connection 8| securing itto the by-pass conduit 65. The action of the spring is such as to maintain the roller 16 at all times pressing against the surface of the cam 18. I

The gate valve 60' operates in response to the rotation of the cam 18 to vary periodically the volume of spinning solution passing through the spinnerette, and hence, also to vary the pressure in the solution passing through the outlet conduit 60. Depending upon the shape of the cam, the pressure can be gradually increased and suddenly relieved to produce a filament approximating the shape of that illustrated in Fig. 6,, or by substituting a cam 85 (Fig. 5) for the cam 18, a filament of another contour canbe produced as illustrated in Fig. '7. It will be noted that the cam'85 is circular and is mounted eocentrically upon the shaft I5.

A vibrating mechanism 90 which is mounted in conjunction with the spinnerette and outlet conduit 60 consists of a strip of resilient metal 9| of the conduit 60. The resilient strip 9| has a lower horizontal section 94, a vertical section 95 and an upper horizontal section 90, the latter of which is secured by means of a set screw 98 upon an upright arm 99 of a bell crank I00. A pivotal connection IOI supports the bell crank upon an extension I02 of the apparatus frame 20, and a. laterally extendin arm I04 of the bell crank is provided with a set screw I05 which is adapted to be screwed down against the upper surface of the extension I02 for the bell crank and thereby regulating and springing the strip 9 I.

The outer end of the upper horizontal section 96 of the resilient strip bears against a vibrator, such as a gear wheel I01, or other notched rotatable element similar to a wheel. This wheel is rigidly mounted upon a rotatably driven shaft I08 which is supported in suitable bearings I I0 carried upon the frame extension I02. By manipulating the set screw I05, the resilient strip 9| can be sprung against the wheel I01 under such pressure as desired. The intensity of vibration of the-strip This vibration is transmitted to the spinnerette 62 and causes small ribs I Ilto collar 93 that is secured As shown diagrammatically in Fig. 10, the filament structure after extrusion through the spinnerette 62 passes around a guide roll I I5 disposed in a tank H6 and thence successively around driven collector rolls III which are driven at a constant peripheral tains a setting bath latter are drawn from I I9 for the filaments and the rolls II!. While the pressure in the outlet conduit periodically increases and decreases, according to the intervals at which the gate valve 60 is operated to vary the amount of spinning solution to be by-passed to the inlet conduit, the rate of supplying spinning solution from the pump nevertheless continues to be substantially constant.

If desired, the filaments structure in which a core or fiber I20 is included. Fibers of cotton, silk, or the like, can be employed for this purpose. Strands of the fiber I20 are drawn through the rear portions of the spinnerette from suitable supply spools IZI through openings I23 which are substantially the same size as the fibers to prevent leakage of the spinning solution. The passage of the fibers through these openings also tends to prevent leakage tending to'occur against the direction of movement of these fibers. The openings in the spinnerette are larger than the fibers and as the latter pass through these openings, they are coated with the spinning solution. The finishedfilament with the fiber core therein has substantially the same tapered shape as ments without the fiber. The purpose of the fibers is to provide a substantial feathering at the smaller tapered end of the finished filament,

60 can be of composite especially when it is to be employed as a synthetic There is thus provided an the art that the invention is not so limited, but

that various changes can be made therein without departing from the spirit of the invention or from the scope of the appended claims.

I claim:

1'. A process for the production of artificial filaments from a spinning solution of organic plastic, the steps which comprise supplying spinning solution at a constant rate from a-pressure source, extruding the filaments under pressure from said source through a spinnerette, withdrawing the extruded filaments from the-spinnerette at substantially constant speed, lay-passing a portion of the solution from a point between the source'of or without the vibrating mechspeed. The tank H6 ,con-x the spinnerette under tension although at constant speed by the collector that impartedto the filapressure and the spinnerette to be resupplied from the pressure source, and periodically varying the volume of solution by-passed back to the source of pressure.

a by-pass conduit connecting the outlet to the inlet forreturning a portion of the spinning solution back to the pump inlet in response to pumping action of the pump through its outlet and before such solution reaches the spinnerette, a valve in the by-pass conduit, and means to operate the valve at predetermined intervals during the operation of the pump whereby the amount of spinning solution supplied to the spinnerette is varied.

3. An apparatus for the production of artificial filaments comprising a spinnerette, a pump having an inlet and an outlet for supplying from the outlet a spinning solution to the spinnerette, a driven transmission for operating the pump, a by-pass conduit connecting the outlet to the inlet for returning a portion of the spinning solution back to the pump inlet in response to pumping action of'the pump through its outlet and before such solution reaches the spinnerette, a valve in the by-pass conduit, a cam included in the transmission, and means operatively connecting the cam to the valve for operating the latter through continually changing positions in the bypass conduit.

4. A process for the production of an artificial filament from a spinning solution .of organic plastic, the steps which comprise supplying .the spinning solution to a spinnerette from a pressure source that feeds the solution at a constant pressure, extruding a filament through the spinnerette in response to the pressure, by-passing a portion of the solution from a point between the source of pressure and the spinnerette backto be resupplied from said pressure source, periodically varying the volume of solution by-passed back to the source of pressure, vibrating the spin-.

nerette while the filamentis being extruded, and collecting the extruded filaments at a constant rate.

5.- In a process" for the production' of artificial filaments from a spinning solution of organic plastic, the steps which comprise pumping the spinning solution through an outlet at a constant rate, extruding under pressure of the pumping action the filaments through a spinnerette capable of extruding only a. fraction of the pumped solution, by-passing under force of the pumping action the remainder of the pumped solution back to the source of pumping to be repumped through the outlet, restricting in progressively increasing and decreasing degrees the passage of the by-passed solution back to the source of pumping to vary the extruding pressure at the spinnerette thereby recurrently forming gradually tapered sections in the extruded filaments, and drawing the extruded filaments away from the spinnerette.

6. In a process for the production of artificial filaments from a spinning solution of organic plastic, the steps which comprise pumping the spinning solution through an outlet at a constant rate, extruding under pressure of the pumping action a fllament through a spinnerette capable of extruding only a fraction of the pumped so-' lution, by-passing under force of said pumping I the filament.

7. An apparatus for the production of artificial filaments comprising a spinnerette, a pump having an inlet and an outlet for supplying the spinning solution from the outlet to the spinnerette, a by-pass conduit connecting the outlet to the inlet for returning a portion of the pumped spinning solution back to the pump inlet in response to the action of the pump before such solution reaches the spinnerette, a valve operable in the bypass conduit at gradually recurring intervals to vary the amount of spinning solution supplied to the spinnerette and thus successively tapering sections of the extruded filament, means for operating said valve at the graduallygrecurring intervals, and vibrating mechanism connected to the spinnerette to impart multiple ribs to the filaments along each tapered section thereof. JOHN J. GREGORY. 

